Fuse plug



July 24, 1928.

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Filed Jan. 16, 1926 I INVENTOR A TTORNEV Patented July 24, 1928.

UNITEE STATES HARRY J. WHEELER, OF KANSAS CITY, MISSOURI.

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Application filed January 16, 1926. Serial No.

My invention relates to fuse plugs, and to devices of this character and forming a part of my pending application, Serial No. 745,- 407, filed Oct. 23. 1924, and the object of the invention is to further improve fuse plugs by providing facilities for renewal of the fuse element and allowing the fuse plug to be used indefinitely.

A further object of the invention is to provide the fuse plug with storage facilities for carrying a supply of fuse elements for use in connection with the plug.

I attain these objects and other advantages by means of the device and combination of parts illustrated in the accompanying drawing in whichFigure 1 is an elevation of a fuse plug embodying my invention; Figure 2 is a vertical section of the fuse plug, on the line 22, in Figure 1; Figure 3 is a plan view of the upper end of the head member of the fuse plug, and showing the storage chamber open; Figure 4t is a plan View of the lower end of the head member, and showing the fuse element mounted thereon in operative position; Figure 5 is plan view of the upper end of the plug member, and showing the bore therein to receive the head member and the yielding conductor members for engaging the fuse element and, Figure 6 is a plan view of the lower end of the plug member.

Similar numerals of reference refer to, corresponding parts through the several views.

The numeral 1 designates a fuse plug which is constructed in accordance with my invention. It comprises a plug member 2 and a head member 3 and which are made of suitable insulating substance, preferably moulded to shape. The members are formed cylindrical with suitable bevels and tapers to make the device appear ornamental. A bore 4; is provided in the upper end of the plug member and extends longitudinally thereof a suitable distance to form a chamher for the reception of the head member. At diametrically opposite sides of the chamber, in the lower end thereof, are through bores 5 and 6 and which extend longitudinally of the plug member. The lower end of the plug member is reduced circumferentially and two diametrically opposite sides of the reduced portion are flattened, as shown at 7 and 8, and the flattened portions recessed a little to have the same register with the inner sides of the respective PLUG.

bores 5 and 6. A conductor 9 of suitable spring metal is extended upwardly in the bore 5 and in the chamber 4 to a point therein intermediate the height of the chamber, the lower end portion of the conductor is bent at right angles and the bent portion secured to the lower end oft-he plug member, by a suitable fastener 10, as shown in Figure 2. A shell 11 of conducting material and having a rolled thread 12 is mounted on the lower portion of the body of the plug member and is adapted to be received by the rolled threads on the conventional socket, not shown, but well understood. A conductor 13 of suitable spring metal is extended upwardly in the bore 6 and in the chamber at to a point therein opposite to the terminal end of the conductor 9, the lower end portion of the conductor is bent at right angles and the bent portion extended through the body of theplug member and secured to the shell 11, as shown in Figure 2.' The chamber is formed to have a greater diameter at its lower end and with a gradual reduction of diameter in upward direction to its entrance, as shown in Figure 2, and for the purpose of allowing the conductors 9 and 13 to yield laterally when the head member is introduced into the plug member, as will be explained. A chamber 15 is formed in the head member to hold a supply of fuse elements 16 for use in connection with the fuse plug. The lower end portion of the head member is reduced circumferentially and two sides thereof flattened and the lower end of the reduced portion is provided with a shallow recess or groove 17 ZLClZLOlIGLl to substantially receive the fuse element 18, as shown in Figure 4E. A'lid 19 is pivotally mounted on the upper end of the head member by a pivot 20 and is adapted to be rotated to close and open the chamber 15. A washer 21 may be secured on the reduced portion of the head member to hold the fuse element in place. Guiding channels 22 are formed in the vertical wall of the chamber 4- at diametrically opposite sides and adapted to receive and guide the reduced portion of the head memher.

To use the fuse plug the head member is separated from the plug member and a fuse element placed in the recess provided for it in the end of the reduced portion of the head member, whereupon the washer 21 may be secured over the fuse element. The end portions of the fuse element are bent up-' ward to lie against the flattened ends'of the reduced end portion of the head member. The reduced portion of the head member is then introduced into chamber 4 in the plug member and the head member pressed down to bear on the plug member. In this action the flattened sides of the reduced portion of the head member enter the guiding slots or channels 22 and the head member being pressed downward the bent portions of the fuse element frictionally engage the inner sides of the conductors 9 and 13 and press the same outward, the reaction of the spring conductors being sufiicient to effect a perfect contact between the conductors and the ends of the fuseelement. The fuse plug is then screwed into the socket, not shown, and the fuse plug is operative. If a fuse element is blown the head member is withdrawn from the plug member and a fuse element 16 istaken from the chamber 15 and placed as before stated and the head member again pressed to place on the plug member.

The fuse plug is free from complications and may be used safely. The storage of a supply of fuse elements in the head member is a provision for quick renewal of the fuse element and obviating the necessity of purchasing a new plug when the. fuse element is blown. be used for an indefinite time. The renewal of the fuse element is effected when the The fuse plug is durable and may head member is withdrawn from the plug member and is a provision for safety. It is impossible to place more than a single fuse element in the groove 17 and therefore an overload is impossible.

Having described my invention what I claim is- In a fuse plug, a socket engaging member comprising a solid body of insulation having a bore in its upper end face forming a fuse receiving chamber and in its lower end face two bores forming terminal housings having communication with opposite sides of said chamber, a threaded metallic sleeve encompassing said body and having a terminal extending through one of said housings to one side of said chamber, a terminal secured to the lower end face of said body and extending through the other one of said housings, to the opposite of chamber, and fuse carrying member fitted to HARRY J. WHEELER. 

